I'm trying to 5 star all of the songs on expert. I've gotten all but about 12. Basically the last two sets of songs minus madhouse and also add tattoed love boys or whatever, I can't seem to nail it well enough.
Practice does make perfect. My advice to those of you having problems with the orange button:
1. Master medium (using the pinky for blue specifically)
2. When you reach hard and especially expert, make your default hand position where your index finger is on the red, middle on yellow, ring on blue, and pinky on orange. It's a lot easier to reach the green button with your index finger than it is the orange button with your pinky. That's my biggest piece of advice and is what helped me the most.
EDIT: This is my first post in like 4 years. Damn my sig needs updated. I'm still using numbers for letters. haha